Man stabbed on friend's doorstep in Livingston
A 29-year-old man was stabbed as he answered the door to his friend's house in West Lothian.
Police are treating the attack, which happened at 2315 GMT on Thursday, as attempted murder.
The suspect stabbed the victim then escaped from the property on Briarbank, in the Ladywell area of Livingston.
Lothian and Borders Police said they wanted to speak to a man who was seen in the area shortly before the attack.
He was described as white, 18 to 22 years old, 5ft 8in (1.7m) to 5ft 10in (1.8m) tall, and of medium build.
He was wearing a cream or fawn-coloured jacket and was unshaven, with short dark hair.
A spokesman for the force said: "We are searching the Briarbank area in an attempt to recover the weapon."
He appealed for anyone who witnessed the incident, saw anyone acting suspiciously in the area or has any other information about the attack to contact police.